SRX SIP packets doesnt flow, instead ICMP

Hi.

network sheme is very simple:

LAN----ge0/0/0.15<SRX>vlan.100----ISP----10.3.7.81

(ISP have host with address from private netw)

So. My aster have address 192.168.77.122 and outgoing SIP session going through source nat rule:

pool PBX {
    address {
        37.230.255.21/32;
    }
}
rule-set NAT {
    from zone trust;
    to zone untrust;
    rule NAT-PBX {
        match {
            source-address 192.168.77.122/32;
        }
        then {
            source-nat {
                pool {
                    PBX;
                    persistent-nat {
                        permit target-host;
                        inactivity-timeout 7200;
                    }
                }
            }
        }
    }
}

I have a problem with connecting to SIP peer with private address:

When I try to ping, I see packets in flow session and in wireshark

When I try to call I see packets in flow session:

Session ID: 175737, Policy name: internet-access/4, Timeout: 16, Valid
In: 192.168.77.122/43112 --> 10.3.7.82/5060;tcp, If: ge-0/0/15.0, Pkts: 3, Bytes: 180
Out: 10.3.7.82/5060 --> x.x.x..21/13234;tcp, If: vlan.100, Pkts: 0, Bytes: 0

but I dont see, packets out from interface (port mirroring)

Where is the problem may ocure